This article is about Igursus, not to be confused with Epigursus.
In the middle of a war, Pandalf needed help to win, so he cast a spell on a mountain and split it in two: From the cold and snowy north face, Ouros was born. From the south face, this hot and mighty volcano called Igursus stood up and started walking.
From the cold base where the mountain used to stand from which Igursus and Ouros were birthed, Cryotan appeared. The other two monsters worked together to seal Cryotan away in ice.